1. Field of Invention
The invention relates to an apparatus that forms an image using toners of a plurality of colors, like a color laser printer.
2. Description of Related Art
There has been a color laser printer that includes a plurality of developing rollers to hold different color toner respectively, a photosensitive medium, an intermediate transfer medium and a transfer roller, mounted in a casing.
First, a color-by-color visible image is sequentially formed on the photosensitive medium then transferred to the intermediate transfer medium by sequentially using yellow, magenta, cyan and black toners held on the respective developing rollers. Thus, a color image is formed on the intermediate transfer medium. The color image is transferred onto a sheet by the transfer roller, and finally, a color image is formed on the sheet.
The color laser printer further includes a cleaning unit that captures toner, which remains on the intermediate transfer medium without being transferred onto the sheet.
The cleaning unit generally includes a cleaning roller that contacts the intermediate transfer medium, a removing roller that contacts the cleaning roller, a wiping blade that contacts the removing roller and a waste toner storage box. When a predetermined bias is applied to the cleaning roller, the toner held on the intermediate transfer medium is captured by the cleaning roller and electrically held thereon. When a predetermined bias is applied to the removing roller, the toner held on the cleaning roller is electrically captured and held on the removing roller. Then, the toner remaining on the removing roller is wiped by the wiping blade, and stored in the waste toner storage box.
The cleaning unit is designed so as to contact and separate from the intermediate transfer medium. The cleaning unit is out of contact with the intermediate transfer medium until a color image is formed onto the intermediate transfer medium. After the color image is transferred onto the sheet, the cleaning unit contacts the intermediate transfer medium to remove the toner remaining on the intermediate transfer medium.
However, if the cleaning roller, the removing roller, the wiping blade and the waste toner storage box are unitized so as to integrally contact and separate from the intermediate transfer medium, the structure for the mechanism is complicated, thereby increasing manufacturing costs.
The inventions described in the following embodiments are made to improve the above-identified related art.
The image forming apparatus of the invention includes a developer cartridge that contains developer, an image holding element that holds the developer, which is supplied from the developer cartridge, to form a visible image, an intermediate transfer element on which the visible image is transferred, a cleaning element that captures the developer from the intermediate transfer element, a removing member that removes the developer from the cleaning element and a mechanism that leaves the cleaning element so as to contact and separate from the intermediate transfer element and contact and separate from the removing member.
According to one aspect of the invention, only the cleaning element is brought into contact with and separated from the intermediate transfer element and the removing member. Thus, the structure of the image forming apparatus can be simplified as compared with that of the related art and manufacturing costs can be reduced.